Aqua Lung Aquaflex Mens Back-Zip Jumpsuits, Black Charcoal, X-Large Long Should fit snug, but not too tight 100% Aqua flex (super-stretch) will stretch 250% more than standard Neoprene Pre-bent arms and knees, entire suit double glued and Blind Stitched inside and out Adjustable Velcro collar - helps keep cold out, non-magnetic #10 YKK zipper Can be worn comfortably by multiple persons with different body types Flexible molded rubber knee pads provide exceptional grip and durability